The Crystal Basilisk is a small reptile resembling a sort of lizard. Its body has a smooth external surface and a "cadet blue" color, though variants in their color exist as compared between the two in "Lion 2: The Movie" and "Lion 4: Alternate Ending", the latter having a "Lochmara blue" skin color. Its eyes are devoid of pupils, leaving a pale turquoise sclera. Its defining feature, which earned the prefix in the name, are the six faceted crystalline spines protruding from its back. The crystalline spines can be colored light neon blue (in "Lion 2: The Movie") or apple green (in "Lion 4: Alternate Ending").
- Despite its appearance, the species is not related to Gems since it does not poof when Lion consumes it in "Lion 2: The Movie" and instead leaves behind a corpse.
- Only the bottom half of the animal was seen in its first appearance, as Lion had eaten the top half.
- Though seemingly not part of the animal, white feathers appear around the corpse of the Crystal Basilisks seen in "Lion 2: The Movie" and Issue 6.